Mill for the refining of cocoa,chocolate,paints and other similar products

ABSTRACT

A mill for refining of cocoa, chocolate, paints, enamels and the like comprising an outer cylindric container, a rotor coaxially mounted within said container, independent means for imparting rotative motion to said outer cylindric container and to said rotor whereby the relative speeds of rotation may be adjusted commensurate with the properties of the particular material to be milled; said rotor being adapted to carry rolls or balls with the same being radially impelled against the inner face of the cylindric container during operation.

United States Patent [191 Consoli Oct. 8, 1974 1 1 MILL FOR THE REFINING OF COCOA,

CHOCOLATE, PAINTS AND OTHER SIMILAR PRODUCTS [75] Inventor: Claudio C. Consoli, Milan, Italy [73] Assignee: Carle & Montanari S.P.A., Milan,

Italy 221 Filed: Sept. 8, 1972 21 Appl. No; 287,240

[30] Foreign Application Priority Data June 30, 1972 Italy 26414/72 [52] CI 241/117, 241/131, 241/176 [51] Int. Cl. B020 15/08 [58] Field of Search 241/103, 110, 117, 118,

1,358,782 11/1920 Philippi 241/122 X 2,295,473 9/1942 I'IOIIStein et a1. 241/131 X 2,413,793 l/l947 Sharp 241/131 X 3,072,348 l/l963 Hiorns 241/103 3,202,364 8/1965 Wieland 241/172 X 3,329,350 7/1967 Wisgerhof et a 241/187 X FOREIGN PATENTS OR APPLICATIONS 1,956,785 6/1970 Germany 241/110 Primary ExaminerGranville Y. Custer, Jr.

' Attorney, Agent, or Firm-Ralph W. Kalish [5 7] ABSTRACT A mill for refining of cocoa, chocolate, paints, enamels and the like comprising an outer cylindric container, a rotor coaxially mounted within said container, independent means for imparting rotative motion to said outer cylindric container and to said rotor whereby the relative speeds of rotation may be adjusted commensurate with the properties of the particular material to be milled; said rotor being adapted to carry rolls or balls with the same being radially impelled against the inner face of the cylindric container during operation.

14 Claims, 2 Drawing Figures 11 l I l 2-/ l i MILL FOR THE REFINING OF COCOA, CHOCOLATE. PAINTS AND OTHER SIMILAR PRODUCTS BACKGROUND AND SUMMARY OF THE INVENTION This invention concerns a mill for the refining of cocoa, chocolate, paints and other similar products.

As is already well known, mills of different design have been long utilized for the refining of cocoa, chocolate, paints and like products.

Recently, a need has arisen to reduce the size of the particles of such different products, while decreasing at the same time the specific consumption of power for each weight unit of processed material.

One of most widely used mills is the so-called ball mill, which consists of a cylindric container wherein metal or ceramic balls are loosely placed.

The inherent drawbacks of mills of such type are that relatively long milling times are required to obtain very fine particles, and that uniform grain sizes cannot be obtained. Moreover, the wear, both of the balls andcontainer, greatly increases when a product is to be milled down to very fine particles.

To have the above stated drawbacks rectified, recourse has been made to a mill consisting of an outer, preferably vertical stationary cylinder, within which a cylindric rotor is rotatably fitted, there being balls or rolls guided along paths defined on the outer surface of said rotor in order to obtain a milling by rolling friction only.

However, even by the latter type of mill, it has not been possible to wholly eliminate the heretofore acknowledged deficiencies. As is well known, the results of a milling operation essentially depend on two factors, i.e., the pressure or impact force by which the material being comminuted is acted upon by the milling elements, and as in the case of a mill consisting of an outer stationary cylinder within which a rotor is revolvingly fitted, the rotary speed of said rotor.

Inasmuch as proper account must be taken of the specific properties of each material to be comminuted if optimum milling results are to be attained, it is apparent that both the milling pressure and the speed of milling elements should be properly adjusted at will to conform with such peculiar properties; howevensuch is not possible with the heretofore known mills.

A further requirement which is not met by the heretofore known mills, is that of continuous operation.

Thus, an object of this invention consists in the provision of a mill wherein the pressure and rotary speed of milling elements can be adjusted at will.

A further object of this invention is the provision of a mill which, in addition to the above stated feature, can be continuously operated.

The above objects are attained in a ball or roller mill for the refining of cocoa, chocolate, paints, enamels and like products, consisting of an outer cylindric container. within which a ball or rolls-supporting rotor is coaxially fitted, with the provision of suitable means through which rotary motions can be independently imparted to both suitably designed outer cylindric container and inner rotor.

A mill designed according to this invention will be now disclosed in the following description, taken with the accompanying drawings, wherein an embodiment of said invention is shown, with such disclosure being exemplary only, and not restrictive.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an axial section of mill, and; FIG. 2 is a section taken on the line II-II of FIG. 1.

DESCRIPTION OF PRACTICAL EMBODIMENT Referring now to said drawings, the mill supporting frame is denoted in its entirety by the reference letter A, while the proper mill is indicated generally by the reference letter B.

Said frame A comprises a base 1, wherefrom a vertical column 2 extends, being said column designed in such a manner as to allow two cantilever supporting arms 3 and 4 to be fitted thereon, the supporting arm being secured to lower end of column, while the supporting arm 4 extends from the top of said column 2.

Supported by the outer ends of cantilever arms 3 and 4 is the proper ball or roller mill B.

As it can be noticed from the accompanying drawings, said mill B comprises an outer cylindric container 5, having upper and lower hubs 6,7, respectively, which are housed in suitable roller bearings 8,9, respectively, with which the outer ends of supporting arms 3 and 4 are fitted. By said roller bearings 8,9, the cylindric container 5 can be turned about its own axis by a motor 10 which drives a pulley 11 or other similar transmission means keyed to lower hub 7 of cylindric container 5. A speed variator, such as a gear box indicated at 10', is provided between the motor 10 and the pulley 11, in order to permit adjustment at will of the rotary speed of cylindric container 5.

Moreover, suitable conventional means (not shown) can be conveniently provided to lock, when required, the cylindric container 5 against any rotary motion.

Coaxially fitted inside of cylindric container 5 is a rotor 12, carrying a plurality of milling rolls 13 on its outer surface, said rolls being accommodated in recesses 14 formed on rotor 12 in such a manner as to be radially impelled against the inner face of cylindric container 5 while the rotor is revolving.

In the considered embodiment, said milling rolls 13, being axially parallel to rotor 12, are solid, but obviously the same might comprise a plurality of relatively shorter rolls, having different shapes and being supported at a number of points; or, if desired, balls can be utilized instead of said rolls.

Said rotor 12 is also provided with upper and lower hubs 15,16, respectively, which are engaged within the hubs 6, 7, respectively, of cylindric container 5, wherein the same are supported by roller bearings 18 and by plain bearings 19. A rotary motion can be imparted to rotor 12 by a motor 20, which a belt transmission indicated'at 21, or the like, and a pulley 22 fastened to lower hub 16 of rotor 12. Even in this latter case, a conventional speed variator such as a gear box indicated at 20 is provided between said motor 20 and pulley 22.

The material to be comminuted is fed by a pump or the like (now shown) through a duct 23, which is secured to upper supporting arm 4, and through a passage 24, as formed in hub 15 of rotor 12, to the interior of cylindric container 5 of mill B. Owing to rotation of rotor 12, and thus of the associated upper hub wherein the passage 24 is formed, the fed material is radially projected against the inner face of cylindric container 5.

While the material is flowing downwardly along the inner face of container 5, the same is acted upon by rolls 13 that are disposed circumferentially of rotor 12; then, on attaining the bottom of said cylindric container 5, said material is discharged through a passage 25 extending through lower hub 16 of rotor 12.

Said passage 25 is connected to an outlet pipe 26 which is suitably connected to a suction pump (not shown) or the like.

The customary sealing means as provided between the rotary and stationary components have not been illustrated in the drawings for facilitating disclosure.

As can be observed from FIG. 2, both ends of rolls 13, as fitted around rotor 12, are seated within expressly provided recesses 14, whereby said rolls 13 are allowed to move radially when rotor 12 is driven by motor 20.

To adapt mill B for the particular properties of the material to be comminuted, it is merely requisite to adjust the speed of rotation of rotor 12 and of cylindric container 5, that is, by adjusting the RPM of rotor 12, the pressure exerted by rolls 13 against the inner face of cylindric container is correspondingly commensurately modified or controlled and thus against the material that is flowing downwardly threalong. While by adjusting the RPM of cylindric container 5, the rotary speed of milling rolls 13 can be increased. This is particularly advantageous because by keeping the RPM of rotor 12 unchanged, and thus with a preset working pressure, the rotary speed of rolls 13 may be increased by increasing the RPM of cylindric container 5 without, however, raising the working pressure of said rolls 13.

It follows that the material to be comminuted is acted upon many times more by the single milling rolls, without however any increase in the pressure which is being exerted by said rolls against the inner face of container 5, and to which the most part of quick wear both of rolls and of increase in said pressure, results in a material increase in the consumption of energy as required for the processing of material.

While the invention has been described in detail with respect to a now preferred embodiment thereof, it is understood that various changes and modifications may be made therein without departing from the spirit and scope of this invention.

Having described my invention what I claim and desire to obtain by Letters Patent is:

l. A mill for grinding cocoa. chocolate, paints, enamels, and the like, comprising means defining an outer cylindrical enclosed casing having an upper end wall, a lower end wall, and an intervening side wall, a cylindrical rotor provided within said casing and having an upper end wall, a lower end wall, and an intervening side wall, said rotor and said casing being co-axial, said rotor having an outside diameter less than the inside diameter of said casing for developing an annular grinding volume therebetween, first means rotatably supporting said casing for rotation about its vertical axis, second means rotatably supporting said rotor for rotation about its vertical axis, first drive means operatively engaged to said casing for effecting rotation thereof, second drive means operatively engaged to said casing for effecting rotation thereof, means defining a raw material inlet at the upper end of said mill communicating with the upper end of said grinding volume, means defining a ground material outlet at the lower end of said mill communicating with the lower end of said grinding volume, and a plurality of grinding rollers disposed within said grinding volume being peripherally spaced about the outer face of the side wall of said rotor, said rollers having their longitudinal axes parallel to the vertical axis of said rotor.

2. A mill as defined in claim 1 and further characterized by speed varying means operatively connected to each of said first and second drive means for providing a differential in the relative rates of rotation of said casing and said rotor.

3. A mill as defined in claim 1 and further characterized by means causing said casing and rotor to rotate in the said direction.

4. A mill as defined in claim 1 and further characterized by means causing rotation of said casing and said rotor in opposite directions.

5. A mill as defined in claim 1 and further characterized by means provided on said rotor engaging said grinding elements for travel through said grinding volume upon rotation upon said rotor, the cross-section of said grinding elements being less than the cross-section of said grinding volume.

6. A mill as defined in claim 5 and further characterized by said means engaging said grinding elements being bracket-like elements provided upon said rotor and slidably engaging the respective grinding elements whereby the latter upon rotation upon said rotor may move relatively with respect to said bracket-like elements under the influence of centrifugal force.

7. A mill as defined in claim 5 and further characterized by said means engaging said grinding elements comprising bracket-like elements provided at the upper and lower ends of said rotor for extension radially outwardly thereof within said grinding volume, said bracket-like elements having recesses opening toward said casing, said recesses receiving portions of said grinding elements, said recesses being of slightly greater crosssectional extent than the received portions of said grinding elements whereby the latter upon rotation of said rotor, under the influence of centrifugal force, will move within said recesses toward said casing.

8. A mill as defined in claim 7 and further characterized by the portions of said grinding elements received within said recesses of said bracket-like elements being of relatively reduced cross-section than the adjacent portions of said grinding elements for maintaining same against vertical displacement, said bracket-like elements having their outer edges terminating spacedly from the inner face of said casing.

9; A mill as defined in claim 8 and further characterized by said grinding elements being elongated rollers having their longitudinal axes parallel to the vertical axis of said rotor and being of like extent whereby grinding action is brought about within the full extent of said grinding volume.

10. A mill as defined in claim 1 and further characterized by said rotor upper end wall being located spacedly downwardly from said casing upper end wall to define a chamber of said raw material inlet means, the lower end wall of said rotor being located spacedly upwardly of said lower end wall of said casing to define a compartment of said ground material outlet means,

said chamber and said compartment respectively communicating with the upper and lower ends of said grinding volume.

11. A mill as defined in claim 1 and further characterized by said first rotatable supporting means comprising upper and lower hubs projecting respectively from the upper and lower end walls of said casing, first bearing means journaling said casing upper hub, second bearing means journaling said casing lower hub, said casing first and second hubs being hollow, said sec,- ond means rotatable supporting said rotor comprising a rotor upper hub projecting from the upper wall of said rotor into said casing upper hub, said rotor having a lower hub extending from its lower end wall into said casing lower hub, means provided within said casing upper and lower end hubs for rotatably supporting the received portions of said rotor upper and lower hubs.

the upper end of said grinding volume, conduit means formed in said rotor upper hub and interconnecting said inlet passage and said inlet chamber, said means defining a ground material outlet comprising said rotor lower end wall being spaced from said casing lower end wall to define an outlet chamber communicating with the lower end of said grinding volume, said lower hub having a co-axial outlet passage, means connecting the lower end of said outlet passage to a point of disposition for ground material, conduit-forming means'provided in said rotor lower hub for interconnecting said outlet passage and said outlet chamber.

13. A mill as defined inclaim 11, and further characterized by said first and second drive means each comprising a prime mover, a speed variator connected to said prime mover, first motion transmitting means connecting the speed variator of said first drive means with said casing lower hub, second transmitting means con,-

said rotor. 

1. A mill for grinding cocoa, chocolate, paints, enamels, and the like, comprising means defining an outer cylindrical enclosed casing having an upper end wall, a lower end wall, and an intervening side wall, a cylindrical rotor provided within said casing and having an upper end wall, a lower end wall, and an intervening side wall, said rotor and said casing being co-axial, said rotor having an outside diameter less than the inside diameter of said casing for developing an annular grinding volume therebetween, first means rotatably supporting said casing for rotation about its vertical axis, second means rotatably supporting said rotor for rotation about its vertical axis, first drive means operatively engaged to said casing for effecting rotation thereof, second drive means operatively engaged to said casing for effecting rotation thereof, means defining a raw material inlet at the upper end of said mill communicating with the upper end of said grinding volume, means defining a ground material outlet at the lower end of said mill communicating with the lower end of said grinding volume, and a plurality of grinding rollers disposed within said grinding volume being peripherally spaced about the outer face of the side wall of said rotor, said rollers having their longitudinal axes parallel to the vertical axis of said rotor.
 2. A mill as defined in claim 1 and further characterized by speed varying means operatively connected to each of said first and second drive means for providing a differential in the relative rates of rotation of said casing and said rotor.
 3. A mill as defined in claim 1 and further characterized by means causing said casing and rotor to rotate in the said direction.
 4. A mill as defined in claim 1 and further characterized by means causing rotation of said casing and said rotor in opposite directions.
 5. A mill as defined in claim 1 and further characterized by means provided on said rotor engaging said grinding elements for travel through said grinding volume upon rotation upon said rotor, the cross-section of said grinding elements being less than the cross-section of said grinding volume.
 6. A mill as defined in claim 5 and further characterized by said means engaging said grinding elements being bracket-like elements provided upon said rotor and slidably engaging the respective grinding elements whereby the latter upon rotation upon said rotor may move relatively with respect to said bracket-like elements under the influence of centrifugal force.
 7. A mill as defined in claim 5 and further characterized by said means engaging said grinding elements comprising bracket-like elements provided at the upper and lower ends of said rotor for extension radially outwardly thereof within said grinding volume, said bracket-like elements having recesses opening toward said casing, said recesses receiving portions of said grinding elements, said recesses being of slightly greater cross-sectional extent than the received portions of said grinding elements whereby the latter upon rotation of said rotor, under the influence of centrifugal force, will move within said recesses toward said casing.
 8. A mill as defined in claim 7 and further characterized by the portions of said grinding elements received within said recesses of said bracket-like elements being of relatively reduced cross-section than the adjacent portions of said grinding elements for maintaining same against vertical displacement, said bracket-like elements having their outer edges terminating spacedly from the inner face of said casing.
 9. A mill as defined in claim 8 and further characterized by said grinding elements being elongated rollers having their longitudinal axes parallel to the vertical axis of said rotor and being of like extent whereby grinding action is brought about within the full extent of said grinding volume.
 10. A mill as defined in claim 1 and further characterized by said rotor upper end wall being located spacedly downwardly from said casing upper end wall to define a chamber of said raw material inlet means, the lower end wall of said rotor being located spacedly upwardly of said lower end wall of said casing to define a compartment of said ground material outlet means, said chamber and said compartment respectively communicating with the upper and lower ends of said grinding volume.
 11. A mill as defined in claim 1 and further characterized by said first rotatable supporting means comprising upper and lower hubs projecting respectively from the upper and lower end walls of said casing, first bearing means journaling said casing upper hub, second bearing means journaling said casing lower hub, said casing first and second hubs being hollow, said second means rotatable supporting said rotor comprising a rotor upper hub projecting from the upper wall of said rotor into said casing upper hub, said rotor having a lower hub extending from its lower end wall into said casing lower hub, means provided within said casing upper and lower end hubs for rotatably supporting the received portions of said rotor upper and lower hubs.
 12. A mill as defined in claim 11 and further characterized by means defining a raw material inlet comprising said rotor upper hub having a co-axial inlet passage, means connecting said passage at its rotor-remote end with a supply of raw material to be ground, said rotor upper end wall being spaced from the casing upper end wall to define an inlet chamber communicating with the upper end of said grinding volume, conduit means formed in said rotor upper hub and interconnecting said inlet passage and said inlet chamber, said means defining a ground material outlet comprising said rotor lower end wall being spaced frOm said casing lower end wall to define an outlet chamber communicating with the lower end of said grinding volume, said lower hub having a co-axial outlet passage, means connecting the lower end of said outlet passage to a point of disposition for ground material, conduit-forming means provided in said rotor lower hub for interconnecting said outlet passage and said outlet chamber.
 13. A mill as defined in claim 11, and further characterized by said first and second drive means each comprising a prime mover, a speed variator connected to said prime mover, first motion transmitting means connecting the speed variator of said first drive means with said casing lower hub, second transmitting means connecting the speed variator of said second drive means with the rotor lower hub.
 14. A mill as defined in claim 1 and further characterized by said grinding rollers being co-extensive with said rotor. 